Explosive



- on the base of the shell.

- UNiTED STATES- PATENT OFFICE.

- WALTER 0. SNELLHTG, 0F ALLENTOWN, PENNSYLVANIA, ASSIGNOB TO TZ BIOJ'AN YOWDEB comm, OF NEW YORK, 11'. Y., A CORPORATION OF NEW YORK.

EXPLOSIVE.

Ho'Draw'lng.

To allaalzom it may concern:

Be it known that I, VVAurnn-O. SNELLING, citizen of the United States, and resident of Allentown, Lehigh county, Pennsylvania, haveinvented certain Improvements in Explosives, of which the following is a specification.-

ldy invention relates to improvements in nit-rostarch explosives, and more particu-' larly to improvements in booster charges for shells, torpedoes and the like.

For the purposes of a booster explosive, a. material must be highly explosive and have great strength, and at the same time be sufiiciently insensitive to be capable of withstanding the heavy shock which is produced on a shell at the moment that it is first moved forward by the powder gases in the-- gun, and also at the moment that its speed is suddenly checked when it reaches its destination.

Heretofore booster charges ha e-usually consisted of compressed pellets of tetryl or T. N. T., these substances having the ability when compressed under a pressure, of 5,000 pounds per square inch or higher, of consolidatin from nlverulent form to yield hard an ness.

lVhile nitroshirch is sulliciently powerful for use as a booster charge. it is in its orrlinary condition too sensitive for the purpose, since it would produce premature explosion from the shock of the powder gases Ordinary nitrostarch, also, is unsatisfactory for use as a booster e losive because of its pulverulent nature and because even pressures much in excess of those which are employed in forming pellets of tetryl or T. N. T. are incapable of bringing about the consolidation of this material. No pressures employed up to this time have proved sulficient to cause nitrostarch to unite to form a firm pellet, such as is required in booster charges.

I have discovered that nitrostarch, when blended with suitable agglomerating and desensitizing material, is capable of forming a booster explosive superior to either tetryl or T. N. '1.

Among the materials with which I have obtained useful results as agglomerating agents are parafiin hydrocarbons, beeswax, ceresin, ozocarite, rosin, and other like materials, these materials preferably being used dense t. blets of suitable sensitive:

Specification ct Letters leatent. Patented June 21, 1921.

Application filed November 3, 1920. Serial; No. 421,475."

sensitiveness. Ordinary nitrostarch is first.

warmed with parallin wax or equivalent being mixed with the agglomemting agent at a temperature at which the waxy matonal 1s semi or completely liquid. Pres- -waxy material, the nitrostarch preferablysure is then applied to the composition to.

form pellets of the desired size and shape, the said pressure preferably approximating. 1000 pounds per squareinch, although higher or lower pressures may be employed, according to the nature of the agglomeratmg material, the temperature employed, and

the percentagezof agglcmerating material used.-

It is frequently desirable to have present in my new booster compositions an oxidizing agent, and in such cases I prepare a mixture of the nitrostarch, the agglomc-rating agent and the oxidizing agent. As an illustration of such a composition," I will describe the method cmpla ed to prepare a booster composition suit le for trench mortar shells.

first. thoroughly mix 40 parts of nitrostarch and 50 parts of anoxidizing agent such as an inorganic nitrate, chlorate or perchlorate. ammonium nitrate being particularly suitable in such composition as I am now describing. I next add to the mixture 2% of a heavy mineral oil as a desensitizing agent, and thoroughly incorporate the entire of pressure. The oil acts to dcsensitize the nitrostasch to the desired extent, while the rosin serves to consolidate the mixture under the influence of the pressure applied to form a pellet of the desired coherence and strength.

It will be noted that the agglomerating agent may be alone relied upon to produce the desired insensitiveness, as in the example first given, or an additional desensitizing agent maybe employed with the agglomerating material as in the second example, the use of these materials depending upon the degree of sensitiveness that it is desired to impart to the explosive, and also upon the nature of the particular agglomeratmg material employed. By varying the proportion of agglomerating agent with respect to the nitrosrarch, and employing an addi ional desensitizing agent as re uired, I can obtain the particular degree 0 sensitiveness I ma words. y my invention I have a booster of controlled sensitiveness.

When ammonium nitrate is employed in the explosive with a temperature in excess of 50 centigrade during the operation of pressing the pellets, there occurs a recrystallization of the ammonium nitrate, this material then tending to set, and thus to add to the strength and coherence of the resulting pellet. In the case of mixtures employing a relatively high percentage of am- .monium nitrate, a lesser quantity of the cementing or agglomerating agent may accordingly be employed than would be used with mixtures containing a lower proportion of the ingredient.

Many equivalent substances may be used in place of the agglomerating and desensitiZing agents h'creinbcfore named, the essential feature of the invention residing in the preparation oi booster compositions of high brisance and great explosive force from nitrostarch by mixing with this material a substance or substances having properties enabling them to act. as desensitizing and agglomerating agents, :nd forming this mixture into masses oi the desired shape and size- The composition is a strong coherent :nax of completely uncolloided nitrostarch.

I claim:

1. As a new composition-oi matter, strong coherent masses comprising entirely uncolloided nitrostarch.

2. As a new composition of matter strong coherent masses comprising uncolloided nitrostarch admixed with an )rganic nitrate.

3. As a new composition of matter, strong coherent masses in tablet form comprising entirely nncolloidcd nitrostarch admixed with an inorganic nitrate and a. readily fusible hydrocarbon body.

4. Abooster charge containing nitrostarch.

5. A booster charge of controlled sensitireness containing nitrostarch.

6. A booster composition comprising nitrostarch desensitized by means of a hydrocarbon body.

7. A booster composition comprising niy trostarch consolidated by means of a waxy require for any particular booster. In other material.

8. A booster composition comprising nitrostarchdesensitized by means of a hydrocarbon body, and consolidated by means of a waxy material.

9. A booster composition comprising nitrostarch, a cementing agent, and an inorganic salt.

10. Abooster composition comprisin nitrostarch, a cementingagent, a desensitizing agent, and an inorganic salt.

11. A boster composition comprising nitrostarch, a desensitizing agent, a cementing agent, and an inorganic nitrate.

12. A booster composition comprising nitrostarch, an inorganic nitrate, and a hydrocarbon material serving to desensitize and consolidate the resulting composition.

13. The method of preparing a booster composition from-nitrostarch, which consists of desensitizing and consolidating said nitrostarch by means ot a hydrocarbon material, and forming said agelomerated'mixtnre into pellets under pressure.

14. The method of preparing a booster composition from nit-rostarch, which consists of consolidating said nitrostarch by means of a waxy material, and compressing said consolidated nitrostarch into pellets.

15. The method of preparing a booster -c0mposition from nitrostarch, which consists of mixing with said nitrostarc-h a desem sit-izing agent, agglomemting sa d desensitized nitrostarch with a cementing agent, and compressing said agglomerated mixture into pellets.

1G. The method of preparing a. booster composition from nitrostarch. which consists of agglomerating said nitrostarch by means of suitable desensitizing and cementing material, and compressing the said mixture into pellets under a pressure of approximately 1000 pounds per square inch.

WALTER O. SNELLING 

